In The Archaeology of Knowledge Foucault lists non-discursive practices as including ‘institutions, political events, economic practices and processes’ (p.162). He also argues that discourse does not underlie all cultural forms. Forms such as art and music are not discursive. He also notes: ‘there is nothing to be gained from describing this autonomous layer of discourses unless one can relate it to other layers, practices, institutions, social relations, political relations, and so on. It is that relationship which has always intrigued me’.